<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>if标签</title>
</head>
<body>
{% if age > 18 %}
    <p>你已满18岁</p>
{% elif age == 18 %}
    <p>你刚满18岁</p>
{% else %}
    <p>你未满18岁</p>
{% endif %}
</body>
</html>